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What to look for in rotary tables?

morsetaper2

Diamond
Joined
Jul 2, 2002
Location
Gaithersburg, MD USA
I have always wanted a rotary table and have always managed to do without. I have a project coming up where it would be nice to have one. So I am going to have a look around.

I have used a rotary table only a couple times at someone elses shop. So I have very limited exposure to them. I'd like to know what i should look for in a rotary table to be used on my vert mill (millrite) with a 7 x 27 table. I am thinking a 6-8 inch diam is what I should be looking at?? I hope to find a decent used American made table.

So I'd appreciatte any advice, pointers, or recomendations on looking for and evaluating rotary tables.

thanks
 
In my first days on ebay, I bid on a Yuasa 8" rotary table. Nobody else bid on it, so I won. It was new in the box, a great deal, till I was informed by a friend that it was a Yuasa "type". Completed the auction, just because it was my mistake, a valuable lesson learned.
I am thinking a 6" would be better for your size table, but if you find a good deal on an 8", I would go for it.
David from Jax
 
when I was young, strong, healthy, and thought nothing of lifting it, a 10" H & V was my first choice. I still think it was a good choice for the work I mostly do, and this is where you may decide to compromise. If you do small work, an 8" table is much lighter and more convenient to set up. Stood vertical, it interferes less with the spindle to reach center. I don't think a 6" is a good choice unless you know you will only be working miniature stuff. You use a considerable percentage of a small table just for set ups and hold down clamps on a lot of work, and a small table does not leave much room.

I like 90:1 gear ratio for circular milling, which is presumably your primary interest with a rotary table. My 10" table is 90:1, and that is a pretty good ratio for milling diameters (hand cranking) out to 12" or so. My 20" table is also only 90:1, and out near or past the rim (I do one part at 32" diameter) that always seems _very_ coarse.

If you plan to use the table for any indexing and dividing work at all, get one that includes a set of dividing plates, index pin, and sectors.

If most of your work is small, round to begin with, and will actually be dividing work, where you index the table, lock it, and then drill a hole or mill a slot with the machine axis drive, you might find a dividing head more useful. For instance, I've made gears on a vertical rotary table, and in a spin index. On the table, you need an insert collet chuck or other arrangement in the center hole to get the work out far enough to clear the cutter. It's a lot more convenient on a dividing head. OTOH, I don't find it fun or convenient to do much circular milling on a dividing head if the work diameter is much over a few inches.

Dividing heads typically are 40:1, so faster to index, position to positon. But the milling capability on a radius is limited by the "coarse" ratio to smaller diameters, as is the usual work holding (collet or chuck) arrangement. A dividing head will tilt from below horizontal to past vertical, so you can mill, drill, bore or shape profiles at any angle in between.

an 8" H & V with dividing plates and set up, can usually be arranged somehow to do most of the work you might want to do on it. It is relatively light to move, and convenient to set up with reasonable space (spindle clearance, e.g.)limitations to be considered. A little bigger (10") is better, if you will ever need the capacity.

smt
 
The Vertex brand ones you see on "the 'Bay" look decent in person, much better IMHO than the Phase II. I wouldn't touch one of the eBay unbranded ones with a ten foot pole. I've seen unbranded ones from India that look like they were cast from old soup cans and machined with an axe. The drawback with the Vertex ones is loss of headroom. A 9" Troyke might be nice for you, as it would only hang over the table sides by 1".
 
I have one those quality import (made in China) 6" rotary table, and unlike some of the imported stuff the rotary tables are actually quite usable. It didn't require the usual tear down, deburring, and lubricating. I regret that I didn't get the 8". As Stephen noted, you run out space rather quickly.

Albert
 
I use a Hoffman 8" rotary table on my Alexander (Deckel FP1 copy) it also has the indexing plates etc, as fitted to dividing heads. It is a really top class bit of kit.
I bought mine in good second hand order for £260 and dont regret it for a moment.
 
Anyone have any experience with a Bison rotary table?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2536249156&category=11805
This is the first time I've seen one. Knowing Bison's reputation, this would be a foreign import I might consider. Plus, Poland is turning out to be quite the ally in todays war on terror!
smile.gif
 
I have a 9" TROYKE that I would sell if your looking for used. It's horz or vertical and very accurate. I'm just up the road from you in Winchester, VA. Asking $500 (they are $1,400 new)John
 








 
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